Abstract

A silicon (Si) nanowire grid ultraviolet (UV) transmission polarizer has been fabricated, and its performance was measured over the visible to deep UV range. A cylinder-forming polystyrene-b-poly(hexylmethacrylate) diblock copolymer was coated onto an amorphous Si layer supported on a fused silica substrate, then shear aligned and employed as a mask for reactive-ion etching, resulting in a Si grid of 33nm period and multi-centimeter-squared area. Due to the high plasma frequency and UV reflectance of the deposited Si, this nanowire grid was able to polarize light down into the deep UV, including 193nm.

Figures (4)

Transmittance of as-deposited Si (open circles) and Al (filled squares) thin films, 25nm thick, on fused silica. Transmittance between 130 and 300nm was measured in vacuum, otherwise in air, and corrected for the transmittance of the support.

(a) Fabrication process for a Si nanowire grid polarizer using block copolymer lithography. (b) Scanning electron micrograph (SEM) image of the finished Si nanowire grid supported on fused silica. Specimen has been cleaved and tilted at 45° away from the viewer to emphasize the profile of the wires.